Botulinum toxin-A effects on pain, somatosensory and psychosocial features of patients with refractory masticatory myofascial pain: a randomized double-blind clinical trial.

The antinociceptive effect of BoNT-A have been well documented in animal studies; however, results of few but well-designed randomized placebo-controlled clinical trials about BoNT-A efficacy in masticatory myofascial pain (MFP) are inconsistent. Therefore, the present randomized, double-blind, placebo-controlled clinical trial evaluated the efficacy of BoNT-A in patients with refractory MFP. Twenty-eight patients with pain reduction of less than 30% despite conservative treatment and with an average pain intensity of > 50 mm on the visual analogue scale (VAS) participated. Patients were randomly assigned to receive a total of 80 U of BoNT-A or saline solution (SS) injected into the masseter and anterior temporalis muscles. Pain intensity (VAS), quantitative sensory testing (QST), conditioned pain modulation (CPM), and psychosocial status were examined. Follow-up was performed at 1 and 6 months. For repeated-measure comparisons between evaluation times, Friedman test with Bonferroni correction was used for pain and somatosensory variables and the Wilcoxon test for the psychosocial variables. The Mann-Whitney test was used for all comparisons between groups. The BoNT-A group had a significant decrease in pain intensity at follow-ups compared with the SS group (p < 0.001). QST assessment revealed higher pressure pain threshold values in the masseter muscle for BoNT-A group compared to SS (p < 0.03) at all follow-ups. No differences were found for mechanical pain threshold and wind-up ratio values (p > 0.05) in the entire study. The BoNT-A group presented the most efficient CPM effect (p < 0.03) only at the 1 month follow-up in the masseter muscle. There was a significant time effect for BoNT-A in all psychosocial variables (p < 0.05) and a drug effect in the Central Sensitization Inventory (p < 0.01), Pittsburgh Sleep Quality Index (p < 0.004), and Healthy Survey 36 (p < 0.05) at 6 months follow-up. The study demonstrates that a single injection-session of BoNT-A has positive effects on the hall pain spectrum of patients with refractory masticatory myofascial pain.

Intramuscular injections of botulinum toxin for the treatment of upper back myofascial pain syndrome: A systematic review of randomized controlled trials.

BACKGROUND AND OBJECTIVE: Myofascial pain syndrome (MPS) is a chronic musculoskeletal disorder characterized by the presence of trigger points. Among the treatment options, botulinum toxin injections have been investigated. The aim of this paper was to provide a synthesis of the evidence on intramuscular botulinum toxin injections for upper back MPS. DATABASES AND DATA TREATMENT: A systematic review of the literature was performed on the PubMed, Scopus and Cochrane Library, using the following formula: ("botulinum") AND ("musculoskeletal") AND ("upper back pain") OR ("myofascial pain"). RESULTS: Ten studies involving 651 patients were included. Patients in the control groups received placebo (saline solution) injections, anaesthetic injections + dry needling or anaesthetic injections. The analysis of the trials revealed modest methodological quality: one "Good quality" study, one "Fair" and the other "Poor". No major complications or serious adverse events were reported. Results provided conflicting evidence and did not demonstrate the superiority of botulinum toxin over comparators. Most of the included trials were characterized by a small sample size, weak power analysis, different clinical scores used and non-comparable follow-up periods. Even if there is no conclusive evidence, the favourable safety profile and the positive results of some secondary endpoints suggest a potentially beneficial action in pain control and quality of life. CONCLUSION: The currently available studies show conflicting results. Their overall low methodological quality does not allow for solid evidence of superiority over other comparison treatments. Further insights are needed to properly profile patients who could benefit more from this peculiar injective approach. SIGNIFICANCE: The randomized controlled trials included in this review compared using botulinum toxin to treat upper back MPS with placebo or active treatments (e.g., dry needling or anaesthetics) showing mixed results overall. Despite the lack of clear evidence of superiority, our study suggests that the use of botulinum toxin should not be discouraged. Its safety profile and encouraging results in pain control, motor recovery and disability reduction make it an interesting treatment, particularly in the subset of patients with moderate to severe chronic pain and active trigger points. To support the safety and efficacy of botulinum toxin, further high-quality studies are needed.

Role of Rehabilitation Exercise on Myofascial Pain Syndrome Causing Upper Back Pain.

Upper back pain is as painful or troublesome as the pain in the lower back or the neck. Myofascial pain syndrome which is most common cause of upper back pain is characterized by localized musculoskeletal pain and tenderness in association with trigger points. The aim of the study was to correlate the improvement of myofascial pain syndrome patients with proper and timely physical therapy. This quasi experimental study was conducted in the department of Physical Medicine and Rehabilitation, Bangabandhu Sheikh Mujib Medical University (BSMMU), Bangladesh, from 1st January 2008 to 31st August 2008 to see the role of rehabilitation exercise on myofascial pain syndrome causing upper back pain. Sixty (60) patients of myofascial pain syndrome causing upper back pain were randomly assigned for treatment; out of which 23(38.33%) were male and 37(61.66%) were female. The male and female ratio was 1:1.6. The patients selected for the trial were divided into two groups: Group A and Group B. In group A (n=28) the patients were treated with thermotherapy- Microwave diathermy, non-steroidal anti inflammatory drugs and activities of daily living instructions and in Group B (n=32) with same interventions in addition to rehabilitation exercises. Treatment duration was 6 weeks. The difference of treatment improvement was statistically significant (p<0.05) from 1st week up to 6th week. After complete course of treatment 67.86% patients in Group A and 78.13% patients in group B reported improvement. So rehabilitation exercises can be a valuable adjunct to other modalities of treatment of myofascial pain syndrome causing upper back pain.

[Intervention effect of Qufeng Gutong Cataplasm on myofascial pain syndrome in rats and its mechanism].

This paper aims to investigate the intervention effect of Qufeng Gutong Cataplasm(QFGT) on myofascial pain syndrome(MPS) in rats and to preliminarily explain its mechanism from the perspective of improving muscle inflammation and pain. Male SD rats were divided into 6 groups, namely normal group, model group, positive control drug(Huoxue Zhitong Ointment, HXZT) group, and low, medium, and high-dose QFGT groups(75, 150, and 300 mg·d~(-1)). The rat model of MPS was established by striking combined with centrifugation for 8 weeks, during which QFGT and HXZT were used for corresponding intervention. Standard VonFrey fiber was used to evaluate the mechanical pain threshold, and acetone was used to detect the cold pain threshold. The electrophysiological activity of muscle at trigger point was detected, and the electromuscular analysis of trigger point was performed. CatWalk gait analyzer was used to detect pain-induced gait adaptation changes. The hematoxylin-eosin(HE) staining was used to observe the pathological changes in muscle and skin tissues at the trigger point of rats. Immunohistochemistry was used to detect the expression of capsaicin receptor transient receptor potential vanilloid 1(TRPV1) in muscle tissues and interleukin(IL)-33 in skin tissues at the trigger point. The protein expression levels of TRPV1, protein kinase B(Akt), phosphorylated protein kinase B(p-Akt), IL-1ß, and tumor necrosis factor-α(TNF-α) in muscle tissues at the trigger point were detected by Western blot. The results showed that as compared with the model group, the mechanical pain threshold and cold pain threshold of rats in other groups were increased after treatment with QFGT. The spontaneous electromyography(EMG) activity was observed in the model group, but QFGT alleviated the EMG activity in a dose-dependent manner. Gait analysis showed that standing duration, average intensity, swing speed, maximum contact point, maximum contact area, paw print length, paw print width, and paw print area were significantly improved in all QFGT groups. Pathological results showed that the disorder of muscle arrangement at the trigger point was decreased, muscle fiber adhesion and atrophy were reduced, and inflammatory cell infiltration was alleviated after treatment with QFGT. In addition, QFGT and HXZT both inhibited the protein expression of TRPV1, PI3K, Akt, p-Akt, IL-1ß, and TNF-α in the muscle tissues of rats with MPS. However, there was no significant difference in the pathological structure and expression of IL-33 in the treated skin as compared with the normal group. The related results have proved that QFGT can inhibit the release of inflammatory factors by inhibiting the TRPV1/PI3K/Akt signaling pathway in the muscle trigger point of rats with MPS and finally attenuate the atrophy and adhesion of local muscles and inflammatory infiltration, thereby relieving the muscle pain of rats with MPS, and local administration has no skin irritation.

Anatomical analysis of the motor endplate zones of the suprascapular nerve to the infraspinatus muscle and its clinical significance in managing pain disorder.

Myofascial pain syndrome caused by myofascial trigger points is a musculoskeletal disorder commonly encountered in clinical practice. The infraspinatus muscle is the region most frequently involved in the myofascial pain syndrome in the scapular region. The characteristics of the myofascial trigger points are that they can be found constantly in the motor endplate zone. However, localizing myofascial trigger points within the motor endplate zone and establishing an accurate injection site of the infraspinatus muscle has been challenging because the anatomical position of the motor endplate zone of the infraspinatus muscle is yet to be described. Therefore, this cadaveric study aimed to scrutinize the motor endplate zone of the infraspinatus muscle, propose potential myofascial trigger points within the muscle, and recommend therapeutic injection sites. Twenty specimens of the infraspinatus muscle for nerve staining and 10 fresh frozen cadavers for evaluation of the injection were used in this study. The number of nerve branches penetrating the infraspinatus muscle and their entry locations were analyzed and photographed. Modified Sihler's staining was performed to examine the motor endplate regions of the infraspinatus muscle. The nerve entry points were mostly observed in the center of the muscle belly. The motor endplate was distributed equally throughout the infraspinatus muscle, but the motor endplate zone was primarily identified in the B area, which is approximately 20-40% proximal to the infraspinatus muscle. The second-most common occurrence of the motor endplate zone was observed in the center of the muscle. These detailed anatomical data would be very helpful in predicting potential pain sites and establishing safe and effective injection treatment using botulinum neurotoxin, steroids, or lidocaine to alleviate the pain disorder of the infraspinatus muscle.

Trigger Point Management.

Trigger points producing myofascial pain syndromes are common in primary care. Located within skeletal muscle, trigger points are taut, band-like nodules capable of producing pain and disability. Some evidence from clinical trials supports massage, physical therapy, and osteopathic manual medicine as first-line less invasive treatment strategies. Trigger points are often treated with injections; although randomized trials have found statistically significant results with trigger point injections, conclusions are limited by low numbers of study participants, difficulty in blinding, the potential for a placebo effect, and lack of posttreatment follow-up. No single pharmacologic agent used in trigger point injections has been proven superior to another, nor has any single agent been proven superior to placebo. Trigger point injections, therefore, should be reserved for patients whose myofascial pain has been refractory to other measures, and family physicians should first employ less invasive treatment strategies. Trigger point management is only one part of a comprehensive, multimodal, and team-based approach to patients with myofascial pain.

Dry needling on latent and active myofascial trigger points versus oral diclofenac in patients with knee osteoarthritis: a randomized controlled trial.

BACKGROUND: Latent and active myofascial trigger points (MTrPs) in knee-associated muscles may play a key role in pain management among patients with knee osteoarthritis (KOA). The aim of this study was to investigate the effect of dry needling treatment on pain intensity, disability, and range of motion (ROM) in patients with KOA. METHODS: This randomized, single-blinded, clinical trial was carried out for 6 weeks of treatment and 6-month follow-up. A total of 98 patients met the entry criteria and were randomly assigned to the dry needling latent and active myofascial trigger point (MTrPs) with the stretching group or the oral diclofenacwith the stretching group. Numeric Pain Rating Scale (NPRS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and ROM were statistically analyzed before and after treatment and at the 6-month follow-up. RESULTS: A total of 42 patients in the dry needling group (DNG) and 35 patients in the diclofenac group (DG), respectively, completed the study, and there was no significant difference in the general data between the two groups. After treatments, both the groups showed a good effect in knee pain, function, and ROM, However, the DNG showed a significantly better result than the DG. Especially in the results of the 6-month follow-up, the DNG showed much better results than the DG. CONCLUSIONS: Dry needling on latent and active MTrPs combined with stretching and oral diclofenac combined with stretching can effectively relieve pain, improve function, and restore knee ROM affected by KOA. However, the effects of dry needling and stretching are better and longer lasting than those of oral diclofenac and stretching for at least 6 months. TRIAL REGISTRATION: Registered in the Chinese Clinical Trial Registry ( www.chictr.org.cn ) in 17/11/2017 with the following code: ChiCTR-INR-17013432.

Ultrasound-guided rhomboid intercostal block versus erector spinae plane block for unilateral dorsal back myofascial pain syndrome: a prospective, randomized trial.

BACKGROUND: The aim of this study was to investigate the effects of erector spinae plane block (ESPB) and rhomboid intercostal block (RIB) on pain, disability, quality of life and patient satisfaction in patients with myofascial pain syndrome (MPS). METHODS: In this prospective randomized controlled double-blind study, 60 patients with a diagnosis of MPS were randomized into two groups. In group ESPB (N.=30), US-guided ESPB was performed, and in group RIB (N.=30), US-guided RIB was performed. The pain severity of the patients was assessed using the Numerical Rating Scale before treatment, and immediately after the intervention, on the first day, and one, two, four and six weeks after the intervention. The Short Form-36 Health Survey (SF-36) for health-related Quality of Life, the Neck Disability Index (NDI), and patient satisfaction were evaluated before treatment and six weeks after treatment. RESULTS: In both groups, significant improvements were observed in all parameters during the six-week follow-up period compared to pretreatment values (P<0.05). There was no statistically significant difference between groups for any parameters at any time interval. CONCLUSIONS: This study showed that ESPB and RIB blocks are effective techniques for pain, disability, and quality of life in patients with MPS. We suggest that the interfascial space can be useful in the administration of analgesic agents for the treatment of MPS.

Ultrasound-Guided Trigger Point Injections for the Treatment of Neck and Back Pain in the Emergency Department: A Randomized Trial.

OBJECTIVES: Patients frequently present to the emergency department (ED) with neck or back pain, which can be difficult to treat. We sought to compare ultrasound-guided trigger point injection (TPI) to standard medications for patients with neck or back pain. METHODS: We performed a single-center, open label, randomized controlled trial on ED patients with neck or back pain from myofascial pain syndrome comparing ultrasound-guided TPIs to those who received the combination of a nonsteroidal anti-inflammatory drug (NSAID) and a muscle relaxant (MR). The primary outcome of this study was the reduction in mean pain score at the time of ED disposition. RESULTS: In total, we analyzed 196 patients. At the time of ED disposition, patients in the TPI group had a mean reduction in their pain scores of 45.0 mm as compared to 49.9 mm in the NSAID plus MR group (difference: 4.9 [95% confidence interval (CI) -3.0 to 12.7], P = .22). At the first reassessment, patients in the TPI group had greater pain reduction by 10.7 mm (95% CI 3.1 to 18.4). The rate of rescue therapy use was higher in the NSAID plus MR group (difference: 17.5% [95% CI 4.4 to 36.2]). CONCLUSIONS: We found no difference in pain reduction at the time of ED disposition between patients randomized to the ultrasound-guided TPI group as compared to those who received an NSAID plus a MR. However, patients in the TPI group had greater pain reduction at the time of first reassessment and lower rates of rescue therapy use.

OnabotulinumtoxinA Injections for the Treatment of Myofascial Pelvic Pain: 12-Year Experience at a Tertiary Care Academic Center.

OBJECTIVE: The aim of this study was to highlight the safety of OnabotulinumtoxinA (BTA) injections, with or without concurrent pudendal nerve block, in treating women with myofascial pelvic pain (MFPP). DESIGN: This was a retrospective cohort study. SETTING: The review was conducted in a tertiary care academic center. Participants/Materials: We conducted a chart review of patients who were diagnosed with MFPP and treated with BTA with or without pudendal nerve block between January 2010 and February 2022. METHODS: BTA was injected transvaginally into the pelvic floor muscle group. The primary outcomes were adverse events after BTA injections, and the secondary outcome was the effect of concomitant pudendal nerve block at the time of BTA injections. RESULTS: The cohort included 182 patients; 103 (56.6%) received BTA injections with pudendal nerve block, and 79 (43.4%) received BTA alone. There were no significant demographic differences between the two groups. Post-treatment complications of BTA administration included worsening of pelvic pain (11.5%), constipation (6.6%), urinary tract infection (2.7%), urinary retention (3.8%), and fecal incontinence (2.7%). No statistical difference was noted in the number of phone calls, patient-initiated electronic messages, emergency room visits, or clinic visits for both groups within 30 days post-treatment. The mean number of total injections was 1.6 in the BTA-only group and 1.7 in the BTA with pudendal block group (p = 0.421). Median time to re-intervention with a second BTA injection was 6.0 months; 5.6 months in the BTA with pudendal block group; and 6.8 months in the BTA-only group, p = 0.46. There were 63 re-intervention events after BTA injections. LIMITATIONS: Limitations of our study include the retrospective design making it vulnerable to missing or incomplete data available for review. CONCLUSION: OnabotulinumtoxinA is beneficial in treating women with MFPP; with a duration of therapeutic effect of approximately 6 months. The use of a concurrent pudendal nerve block did not impact clinical outcomes.

Efficacy of ultrasound-guided infiltration with levobupivacaine and triamcinolone for myofascial pain syndrome of the quadratus lumborum: a retrospective observational study.

INTRODUCTION AND OBJECTIVES: Myofascial Pain Syndrome (MPS) of the Quadratus Lumborum muscle (QL) is a frequent cause of chronic low back pain. With this study, we aimed to assess the efficacy of ultrasound-guided infiltration with 0.25% levobupivacaine and 40.ßmg triamcinolone for MPS of the QL. METHODS: Observational and retrospective study of participants submitted to ultrasound-guided infiltration of the QL muscle from January 1, 2015 to June 31, 2019. Pain intensity was assessed using the five-point pain Numeric Rating Scale (NRS): pre-intervention, at 72.ßhours, 1 month, 3 months and 6 months post-intervention. Additional data collected were demographic characteristics, opioid consumption, and adverse effects. RESULTS: We assessed 90 participants with mean age of 55.2 years. Sixty-eight percent of participants were female. Compared to the pre-intervention assessment, there was an improvement in pain at 72.ßhours (Mean Difference [MD.ß=.ß3.085]; 95% CI: 2.200...3.970, p.ß<.ß0.05), at the 1st month (MD.ß=.ß2.644; 95% CI: 1.667...3.621, p.ß<.ß 0.05), at the 3rdmonth (MD.ß=.ß2.017; 95% CI: 0.202...2.729, p.ß<.ß0.05) and at the 6th month (MD.ß=.ß1.339; 95% CI 0.378...2.300, p.ß<.ß0.05), post-intervention. No statistically significant differences in opioid consumption were observed. No adverse effects associated with the technique were reported. CONCLUSIONS: Ultrasound-guided infiltration of the QL muscle is a safe and effective procedure for the treatment of pain in the QL MPS within 6 months post-intervention.

Intervention effect of Qufeng Gutong Cataplasm on myofascial pain syndrome in rats and its mechanism / 中国中药杂志

This paper aims to investigate the intervention effect of Qufeng Gutong Cataplasm(QFGT) on myofascial pain syndrome(MPS) in rats and to preliminarily explain its mechanism from the perspective of improving muscle inflammation and pain. Male SD rats were divided into 6 groups, namely normal group, model group, positive control drug(Huoxue Zhitong Ointment, HXZT) group, and low, medium, and high-dose QFGT groups(75, 150, and 300 mg·d~(-1)). The rat model of MPS was established by striking combined with centrifugation for 8 weeks, during which QFGT and HXZT were used for corresponding intervention. Standard VonFrey fiber was used to evaluate the mechanical pain threshold, and acetone was used to detect the cold pain threshold. The electrophysiological activity of muscle at trigger point was detected, and the electromuscular analysis of trigger point was performed. CatWalk gait analyzer was used to detect pain-induced gait adaptation changes. The hematoxylin-eosin(HE) staining was used to observe the pathological changes in muscle and skin tissues at the trigger point of rats. Immunohistochemistry was used to detect the expression of capsaicin receptor transient receptor potential vanilloid 1(TRPV1) in muscle tissues and interleukin(IL)-33 in skin tissues at the trigger point. The protein expression levels of TRPV1, protein kinase B(Akt), phosphorylated protein kinase B(p-Akt), IL-1β, and tumor necrosis factor-α(TNF-α) in muscle tissues at the trigger point were detected by Western blot. The results showed that as compared with the model group, the mechanical pain threshold and cold pain threshold of rats in other groups were increased after treatment with QFGT. The spontaneous electromyography(EMG) activity was observed in the model group, but QFGT alleviated the EMG activity in a dose-dependent manner. Gait analysis showed that standing duration, average intensity, swing speed, maximum contact point, maximum contact area, paw print length, paw print width, and paw print area were significantly improved in all QFGT groups. Pathological results showed that the disorder of muscle arrangement at the trigger point was decreased, muscle fiber adhesion and atrophy were reduced, and inflammatory cell infiltration was alleviated after treatment with QFGT. In addition, QFGT and HXZT both inhibited the protein expression of TRPV1, PI3K, Akt, p-Akt, IL-1β, and TNF-α in the muscle tissues of rats with MPS. However, there was no significant difference in the pathological structure and expression of IL-33 in the treated skin as compared with the normal group. The related results have proved that QFGT can inhibit the release of inflammatory factors by inhibiting the TRPV1/PI3K/Akt signaling pathway in the muscle trigger point of rats with MPS and finally attenuate the atrophy and adhesion of local muscles and inflammatory infiltration, thereby relieving the muscle pain of rats with MPS, and local administration has no skin irritation.

Ultrasound-guided rhomboid intercostal block for myofascial pain syndrome: a prospective clinical study.

BACKGROUND: Myofascial pain syndrome (MPS) is a common chronic pain syndrome that may affect quality of life, daily living activities, and psychological status. Ultrasound (US)-guided rhomboid intercostal block (RIB) is a recently defined plane block and used for chronic pain such as postmastectomy syndrome and MPS. Our aim was to evaluate the efficacy of US-guided RIB for the management of pain, quality of life, physical disability, and patient satisfaction in MPS. METHODS: In this prospective study, between February and March 2021, a total of 30 patients who applied with the diagnosis of MPS, were included. The patients received US-guided RIB. Pain intensity was evaluated using a numerical rating scale (NRS) at pretreatment, and just after the intervention, at day 1, and 1, 2, 4, and 6 weeks after the intervention. At pretreatment and 6 weeks after treatment, Short Form-36 Health Survey (SF-36) for health-related quality of life, Neck Disability Index (NDI), and patient satisfaction were evaluated. RESULTS: There was a statistically significant decrease in average NRS immediately after treatment, at day 1 and week 1,2,4, and 6 compared to the pretreatment (p < 0.0001). The average SF-36 scores advanced at 6 weeks after treatment. There was a statistically significant reduction in mean NDI scores throughout the follow-up period (p < 0.001). DISCUSSION: Our study demonstrated that RIB had improved neck function, physical and mental quality of life, and patient satisfaction in MPS. Therefore, we think US-guided RIB could be an alternative treatment modality in patients suffering from MPS.

Long-Term Effects of a Single Application of Botulinum Toxin Type A in Temporomandibular Myofascial Pain Patients: A Controlled Clinical Trial.

This study assessed the long-term effects of botulinum toxin type A (BoNT-A) in subjective pain, pain sensibility, and muscle thickness in persistent myofascial temporomandibular-disorder pain (MFP-TMD) patients. Fourteen female subjects with persistent MFP received BoNT-A treatment with different doses (10U-25U for temporalis muscle and 30U-75U for masseter muscle). The treatment was injected bilaterally in the masseter and anterior temporalis muscles in a single session. Clinical measurements included: self-perceived pain (VAS), pain sensibility (PPT), and muscles thickness (ultrasonography). Follow-up occurred 1, 3, 6, and 72 months after treatment for VAS and PPT and 1, 3, and 72 months for ultrasonography. For statistical analysis, the Friedman test with the Bonferroni test for multiple comparisons as a post hoc test was used for non-parametric repeated measures comparisons among the evaluation times. A 5% probability level was considered significant in all tests. VAS values presented a significant decrease throughout the study (p < 0.05). Regarding PPT values, a significant increase was found when comparing baseline data with post-treatment follow-ups (p < 0.05), and even though a significant decrease was found in muscle thickness when baseline values were compared with the 1- and 3-months assessments, no differences were found when compared with the 72 months follow-up (p > 0.05). A single injection of BoNT-A presents long-term effects in reducing pain in persistent MFP-TMD patients, and a reversibility of adverse effects on masticatory-muscle thickness.

Effect of ischemic compression on myofascial pain syndrome: a systematic review and meta-analysis.

BACKGROUND: Myofascial pain syndrome (MPS) is a condition with local and referred pain characterized by trigger points (taut bands within the muscle). Ischemic compression is a noninvasive manual therapy technique that has been employed for the treatment of MPS in past decades. However, little attention has been devoted to this topic. OBJECTIVES: The present review was designed to explore the efficacy of ischemic compression for myofascial pain syndrome by performing a descriptive systematic review and a meta-analysis to estimate the effect of ischemic compression on MPS. METHODS: A systematic review and meta-analysis concerning randomized controlled trials (RCTs) with myofascial pain subjects who received ischemic compression versus placebo, sham, or usual interventions. Five databases (PubMed, The Cochrane Library, Embase, Web of Science, Ovid) were searched from the earliest data available to 2022.1.2. The standardized mean difference (SMD) and the 95% confidence interval (CI) were used for statistics. Version 2 of the Cochrane risk of tool 2 (RoB 2) was used to assess the quality of the included RCTs. RESULTS: Seventeen studies were included in the systematic review, and 15 studies were included in the meta-analysis. For the pressure pain threshold (PPT) index, 11 studies and 427 subjects demonstrated statistically significant differences compared with the control at posttreatment (SMD = 0.67, 95% CI [0.35, 0.98], P < 0.0001, I2 = 59%). For visual analog scale (VAS) or numeric rating scale (NRS) indices, 7 studies and 251 subjects demonstrated that there was no significant difference between ischemic compression and controls posttreatment (SMD = - 0.22, 95% CI [- 0.53, 0.09], P = 0.16, I2 = 33%). CONCLUSION: Ischemic compression, as a conservative and noninvasive therapy, only enhanced tolerance to pain in MPS subjects compared with inactive control. Furthermore, there was no evidence of benefit for self-reported pain. The number of currently included subjects was relatively small, so the conclusion may be changed by future studies. Big scale RCTs with more subjects will be critical in future.

Therapeutic ultrasound versus injection of local anesthetic in the treatment of women with chronic pelvic pain secondary to abdominal myofascial syndrome: a randomized clinical trial.

BACKGROUND: Chronic pelvic pain (CPP) is defined as recurrent or continuous pain in the lower abdomen or pelvis, either non-menstrual or noncyclical, lasting for at least 6 months. There is strong evidence that up to 85% of patients with CPP have serious dysfunctions of the musculoskeletal system, including abdominal myofascial pain syndrome (AMPS). AMPS is characterized by intense and deep abdominal pain, originating from hyperirritable trigger points, usually located within a musculoskeletal band or its lining fascia. In the literature, there are few studies that address AMPS. OBJECTIVES: To evaluate and compare the efficacy of therapeutic ultrasound (TUS) and injection of local anesthetic (IA) to improve pain in women with abdominal myofascial syndrome secondary to CPP. STUDY DESIGN: Randomized controlled clinical trial. SETTING: Tertiary University Hospital. MATERIALS AND METHODS: A randomized clinical trial was conducted, patients were allocated to two types of treatment: group TUS (n = 18), and group IA (n = 20). The instruments used for evaluation and reassessment were the Visual Analog Scale, Numerical Categorical Scale, McGill Pain Questionnaire, and SF-36 quality of life assessment questionnaire. They were evaluated before starting treatment, 1 week after the end of treatment, and at 1, 3, and 6 months. RESULTS: TUS and IA were effective in reducing clinical pain and improving quality of life through the variables analyzed among study participants. There was no significant difference between groups. LIMITATIONS: absence of blinding; exclusion of women with comorbidities and other causes of CPP, the absence of a placebo group, the difference between the number of sessions used for each technique, and the COVID-19. CONCLUSION: Treatment with TUS and IA were effective in reducing clinical pain and improving quality of life in women with AMPS secondary to CPP. TRAIL REGISTRATION: We declare that this clinical trial has been registered under the number [(ReBEC) no. RBR-39czsv] on 07/18/2018 in the Brazilian Registry of Clinical Trials.

Effects of botulinum toxin in patients with myofascial pain related to temporomandibular joint disorders: A systematic review.

Botulinum toxin is used as an alternative for the treatment of chronic refractory myofascial pain derived from temporomandibular disorders (TMDs). It is important to establish the benefits of botulinum toxin in this type of symptomatology. The aim of the study was to conduct a systematic review in order to evaluate the effects of botulinum toxin in patients with myofascial pain related to temporomandibular disorders. The search was carried out systematically, without limitations of language or year of publication, until February 2021. The databases searched included PubMed, Web of Science, Scopus, The Cochrane Library, and Latin American and Carribean Health Sciences Literature (LILACS). Partial gray literature was searched using Google Scholar, ClinicalTrials.gov, OpenGrey, and the reference lists of selected articles. Randomized controlled clinical trials evaluating the effects of botulinum toxin in the treatment of myofascial pain were included. The risk of bias was assessed with the Cochrane RoB 2.0 tool, and the The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to determine the certainty of the scientific evidence. A total of 900 studies were retrieved, out of which only 8 randomized clinical trials were selected. From these 8 studies, the data of a total of 314 patients, predominantly women, between the ages of 18 to 75 years was obtained. After the assessment of the studies with the RoB 2.0 tool, 7 studies showed some concerns regarding the reported results and only one was at a low risk of overall bias. The analysis of the studies has shown that low doses of botulinum toxin are effective in the treatment of refractory myofascial pain associated with temporomandibular disorders. The studies presented mediumto low-certainty evidence..

Efficacy of Botulinum Toxin Type-A I in the Improvement of Mandibular Motion and Muscle Sensibility in Myofascial Pain TMD Subjects: A Randomized Controlled Trial.

This study assessed the effects of botulinum toxin type A (BoNT-A) in mandibular range of motion and muscle tenderness to palpation in persistent myofascial pain (MFP) patients (ReBEC RBR-2d4vvv). Eighty consecutive female subjects with persistent MFP, were randomly divided into four groups (n = 20): three BoNT-A groups with different doses and a saline solution group (placebo control group). Treatments were injected bilaterally in the masseter and anterior temporalis muscle in a single session. Clinical measurements of mandibular movements included: pain-free opening, maximum unassisted and assisted opening, and right and left lateral excursions. Palpation tests were performed bilaterally in the masseter and temporalis muscle. Follow-up occurred 28 and 180 days after treatment. For the statistical analysis the Mann-Whitney U-test with Bonferroni correction was used for groups comparisons. Regardless of dose, all parameters of mandibular range of motion significantly improved after 180 days in all BoNT-A groups, compared with the control group. Palpation pain over the masseter and temporalis muscles were significantly reduced in all BoNT-A groups regardless of dose, compared with the control group, after 28 and 180 days of treatment. Independent of doses, BoNT-A improved mandibular range of motion and muscle tenderness to palpation in persistent MFP patients.

Guidance to trigger point injection for treating myofascial pain syndrome: Intramuscular neural distribution of the quadratus lumborum.

Postural habits and repetitive motion contribute toward the progress of myofascial pain by affecting overload on specific muscles, the quadratus lumborum (QL) muscle being the most frequently involved. The therapy of myofascial pain syndrome includes the release of myofascial pain syndrome using injective agents such as botulinum neurotoxin, lidocaine, steroids, and normal saline. However, an optimal injection point has not been established for the QL muscle. This study aimed to propose an optimal injection point for this muscle by studying its intramuscular neural distribution using the whole mount staining method. A modified Sihler's procedure was completed on 15 QL muscles to visualize the intramuscular arborization areas in terms of the inferior border of the 12th rib, the transverse processes of L1-L4, and the iliac crest. The intramuscular neural distribution of the QL had the densely arborized areas in the three lateral portions of L3-L4 and L4-L5 and the medial portion between L4 and L5.